30 VETERINARY PARASITOLOGY 
parasitic, and there is little pruritus. The wool often 
falls out in patches, but the typical symptoms of scab 
are absent. 
3. Phthiriasis—Trichodectes are found around the 
point of the shoulder, and could be only with difficulty 
confounded with Psoroptes. 
4. Sheep are sometimes the subjects of an ecthyma, 
which is seen on the inside of the elbows and between 
the thighs, but this could scarcely be confused with 
scab. 
Treatment.—This must be divided into preventive 
and curative. 
Preventive treatment comprises the prevention of 
primary infection and of infection of the rest of the flock 
after the disease has appeared in certain members of it. 
As sheep scab is a scheduled disease, the Board of 
Agriculture lays down a series of regulations, with the 
object of preventing and stamping out the disease. 
The Sheep Scab Order of 1905 is the last issued, and 
its provisions, in brief, are as follows : 
All suspected cases must be reported to the police, 
who call upon a veterinary surgeon to verify the 
diagnosis. The premises on which the sheep are kept 
are disinfected and the sheep dipped. It is illegal to 
expose infected sheep in a market for sale, and no sheep 
are allowed to be removed from the scheduled area 
without a licence. In districts where the disease is 
prevalent dipping of all sheep is made compulsory, and 
every owner of sheep is compelled to send in a return 
of the number he possesses. 
Before an owner can remove sheep from the scheduled 
area, he must produce an order, showing that they have 
been dipped satisfactorily, within a period of twenty- 
eight days from the time at which he wishes to remove 
them. 
In districts where the disease is prevalent the farmer 
